/* Global reset */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Theme variables */
:root {
  --primary: #1A4B84;
  --accent: #60a5fa;
  --bg: #0f172a;
  --text: #e2e8f0;
  --card-text: #1a1a1a; /* dark text */
  --card-heading: #0f0f0f;
  --card-bg: rgba(30, 41, 59, 0.85);
  --card-soft: rgba(255, 255, 255, 0.7); /* light glass */
  --radius: 8px;
  --shadow: 0 2px 6px rgba(0,0,0,0.08);
}
.dark-mode {
  --card-soft: rgba(0, 0, 0, 0.35);      /* dark glass */
  --card-text: #e5e7eb;                  /* light text */
  --card-heading: #f8fafc;               /* bright heading */
}

[data-theme="light"] {
  --bg: #f5f7fa;
  --text: #111827;
  --card-bg: #ffffff;
  --card-soft: rgba(0, 0, 0, 0.04);
  --accent: #1A4B84;
}

/* Global layout */
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: var(--bg);
  color: var(--text);
}

/* Animated data grid background */
.data-grid-bg {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: -1;
  animation: gridMove 18s linear infinite;
}

@keyframes gridMove {
  from { transform: translateY(0); }
  to { transform: translateY(-40px); }
}

html {
  scroll-behavior: smooth;
}

/* Sections */
section {
  padding: 80px 20px;
}

/* Header layout */
.site-header {
  background-color: rgba(15, 23, 42, 0.85);
  color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  flex-wrap: wrap;
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.ndh-logo svg {
  height: 40px;
  width: auto;
  transition: transform 0.3s ease;
}

.ndh-logo svg:hover {
  transform: scale(1.08);
}

.logo-text {
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.site-header nav {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-header nav a {
  color: #cbd5f5;
  text-decoration: none;
  font-weight: 500;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.site-header nav a:hover {
  background-color: rgba(148, 163, 253, 0.18);
  color: #ffffff;
}

/* Theme toggle */
.theme-toggle {
  margin-left: 1rem;
  border: none;
  background: rgba(15, 23, 42, 0.8);
  color: #f9fafb;
  border-radius: 999px;
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  box-shadow: 0 0 0 1px rgba(148, 163, 253, 0.4);
  transition: background-color 0.2s ease, transform 0.1s ease;
}

.theme-toggle:hover {
  background-color: rgba(30, 64, 175, 0.9);
  transform: translateY(-1px);
}

@media (max-width: 600px) {
  .site-header {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.6rem;
  }

  .site-header nav {
    justify-content: center;
  }
}

/* Hero section */
.hero {
  max-width: 900px;
  margin: 40px auto 0;
  background: var(--card-bg);
  padding: 120px 20px 80px;
  text-align: center;
  border-radius: 16px;
  box-shadow: 0 0 30px rgba(15, 23, 42, 0.6);
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 20px;
  color: var(--accent);
}

.hero p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: auto;
}

/* Intro section */
section.intro {
  max-width: 900px;
  margin: 40px auto;
  background: var(--card-bg);
  border-radius: 16px;
  box-shadow: 0 0 24px rgba(15, 23, 42, 0.5);
}

section.intro h2 {
  color: var(--text);
  text-align: center;
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

section.intro p {
  color: var(--text);
  text-align: center;
  font-size: 1.1rem;
  font-weight: 400;
  max-width: 700px;
  line-height: 1.6;
  margin: 0 auto 1.5rem;
}

/* Feature grid */
.feature-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2rem;
  padding: 3rem 1rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
}

.feature-card {
  flex: 1 1 260px;
  max-width: 280px;
  background: var(--card-soft);
  border-radius: 14px;
  padding: 2rem 1.5rem;
  text-align: center;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 4px 14px rgba(0,0,0,0.25);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
  opacity: 0;
  transform: translateY(20px);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 10px 24px rgba(0,0,0,0.35);
  background-color: rgba(148, 163, 253, 0.08);
}

.feature-card .icon {
  font-size: 2.4rem;
  margin-bottom: 1rem;
}
.feature-card h3 {
  font-size: 1.4rem;
  margin-bottom: 0.6rem;
  color: var(--card-heading);
}

.feature-card p {
  font-size: 1rem;
  color: var(--card-text);
  line-height: 1.5;
}
.feature-card h3,
.feature-card p {
  text-shadow: 0 1px 2px rgba(0,0,0,0.15);
}
.feature-card.featured {
  border: 1px solid rgba(129, 140, 248, 0.7);
  box-shadow: 0 0 24px rgba(129, 140, 248, 0.5);
}

.feature-card.visible {
  opacity: 1;
  transform: translateY(0);
}


@media (max-width: 900px) {
  .feature-card {
    max-width: 45%;
  }
}

@media (max-width: 600px) {
  .feature-grid {
    flex-direction: column;
    align-items: center;
  }

  .feature-card {
    max-width: 90%;
  }
}

/* App section */
.page-section {
  max-width: 900px;
  margin: 40px auto 0;
  padding: 60px 20px 40px;
  background: var(--card-bg);
  border-radius: 16px;
  box-shadow: 0 0 24px rgba(15, 23, 42, 0.6);
}

.page-section h1 {
  color: var(--accent);
  font-weight: 700;
  font-size: 2.2rem;
  text-align: center;
  margin-bottom: 0.5rem;
}

.page-section p {
  color: var(--text);
  text-align: center;
}

/* App card */
.app-card {
  margin-top: 2.5rem;
  background: var(--card-soft);
  border: 1px solid rgba(148, 163, 253, 0.4);
  padding: 3rem 2rem;
  border-radius: 16px;
  text-align: center;
  backdrop-filter: blur(8px);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  justify-self: center;
  margin-left: auto;
  margin-right: auto;
}

.app-card h3 {
   color: var(--card-heading);
}

.app-card p {
  color: var(--card-text);
}

.app-card h3,
.app-card p {
  text-shadow: 0 1px 2px rgba(0,0,0,0.15);
}

.app-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 0 28px rgba(56, 189, 248, 0.45),
              0 0 12px rgba(139, 92, 246, 0.35);
  border-color: rgba(139, 92, 246, 0.6);
}

.app-card .card-icon {
  font-size: 2.4rem;
  margin-bottom: 1rem;
}

.app-card .card-button {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.7rem 1.4rem;
  border-radius: 10px;
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  color: white;
  text-decoration: none;
  font-weight: 600;
  transition: opacity 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 0 10px rgba(139, 92, 246, 0.25);
}

.app-card .card-button:hover {
  opacity: 0.9;
  box-shadow: 0 0 16px rgba(139, 92, 246, 0.4);
}

/* Contact section */
.contact-section {
  max-width: 900px;
  margin: 40px auto 60px;
  background: var(--card-bg);
  padding: 3rem 2rem;
  border-radius: 16px;
  color: var(--text);
  backdrop-filter: blur(8px);
  box-shadow: 0 0 24px rgba(15, 23, 42, 0.6);
}

.contact-section h2 {
  font-size: 2.2rem;
  margin-bottom: 2rem;
  font-weight: 600;
  text-align: center;
}

.contact-form {
  max-width: 600px;
  margin: 0 auto;
  display: grid;
  gap: 1.2rem;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 1rem;
  border-radius: 8px;
  font-size: 1rem;
  border: 1px solid rgba(148, 163, 253, 0.4);
  background-color: rgba(15, 23, 42, 0.9);
  color: #e5e7eb;
}

[data-theme="light"] .contact-form input,
[data-theme="light"] .contact-form textarea {
  background-color: #ffffff;
  color: #111827;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: #9ca3af;
}

.contact-form button {
  background-color: #3b82f6;
  color: white;
  border: none;
  padding: 1rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.contact-form button:hover {
  background-color: #2563eb;
}

/* Footer */
.site-footer {
  background-color: rgba(15, 23, 42, 0.9);
  color: white;
  padding: 2rem 1rem;
  text-align: center;
  backdrop-filter: blur(8px);
}

.site-footer .footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.site-footer .social-icons a {
  font-size: 1.8rem;
  margin: 0 0.5rem;
  color: white;
  text-decoration: none;
  transition: transform 0.2s ease;
}

.site-footer .social-icons a:hover {
  transform: scale(1.2);
}

/* Video card animation (kept for other pages) */
.video-card {
  background: var(--card-soft);
  padding: 1rem;
  border-radius: 12px;
  backdrop-filter: blur(6px);
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.video-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.video-card iframe {
  width: 100%;
  height: 200px;
  border-radius: 8px;
  border: none;
}

/* Video grids (for videos page) */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
  padding: 20px;
}

.video-card {
  background: var(--card-soft);
  border: 1px solid rgba(148, 163, 253, 0.2);
  padding: 1.2rem;
  border-radius: 14px;
  backdrop-filter: blur(6px);
  color: var(--text);
}
.video-card iframe {
  width: 100%;
  height: 200px;
  border: none;
  border-radius: 8px;
}

.video-card h3 {
  margin-top: 12px;
  font-size: 1.2rem;
  color: var(--card-heading);
}

.video-card p {
  margin-top: 8px;
  line-height: 1.4;
  color: var(--card-text);
}
.video-card h3,
.video-card p {
  text-shadow: 0 1px 2px rgba(0,0,0,0.15);
}
@media (max-width: 900px) {
  .video-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .video-grid {
    grid-template-columns: 1fr;
    padding: 1rem;
  }
}
.video-grid .video-card {
  opacity: 1 !important;
  transform: translateY(0) !important;
}